Updated: Aug 24, 2018
The annoying use of the hashtag sign does have a purpose.
Think of it as a label for content to help others who are interested in a certain topic quickly find content about that topic.
Using it before a relevant keyword or phrase in a Tweet categorizes your post and helps it appear in Twitter search. Think of it as a type of filing system.
When you click on a hashtagged word you will see other tweets that it have used it.
Where you at with @?
Officially, this symbol is called commercial at. Unofficially, most people seem to refer to it as the at sign or just at.
It's used for mentioning or tagging individuals, groups and businesses and when its used in front of their name it tags their account.
When used on Twitter it remains as part of tweet or post while on other social media such as Facebook, if the person tagged in a registered as a member, it disappears and simply shows their name as a link to their page. Thus, it notifies them you have included them in your post.
Social media users have a choice to allow automatic tagging by others or they can opt to be notified and choose to review the post before publishing it to their page or timeline.
When the person approves the tag those who follow their activity will also see your post so it’s a great way to get known if used wisely.
If you need to know more email email@example.com.